PHOTOS: Wrigley Immigration Protest

Last week, Senate Democrats surprised immigrant groups when they announced they would attach the pending legislation, to a defense reauthorization bill already headed for a vote. Now a vote on the legislation could happen Tuesday, according to the Chicago Tribune.

That's why several activists in Chicago launched an urgent campaign to encourage suppporters to flood their senators with calls to pass the Dream Act. Some groups are even using Facebook to encourage participation.

More than 100 undocumented students also plan to rally today outside a U.S. Air Force recruitment office at Federal Plaza around 4 pm. A few students will try to enlist. Then they plan to march to Republican Party headquarters downtown where they will have an overnight vigil, hoping lawmakers will listen and vote "yes" for the DREAM Act.